This invention relates to a magnetic resonance imaging method and apparatus.
The following procedure is employed in a conventional magnetic resonance imaging apparatus to obtain a sectional image corresponding to a desired section of an object to be examined.
First of all, a so-called "scout view" as a sectional image along a body axis of an object to be examined is displayed on a screen of a display device. Line cursors representing a slice portion in this scout view are moved and a sectional image sliced at a desired cursor position is displayed on the screen. The line cursors representing the slice portion of this sectional image are further moved, and a sectional image sliced at a desired cursor position is displayed on the screen.
The sectional image finally obtained in this way is an image along each line cursor, that is, an image of a section sliced on a plane required by an operator.
However, the sectional image finally obtained is displayed in some cases a little to the right or left of the center on the screen of the display device depending on the position of the object inside a gantry.
Therefore, according to the prior art, a point cursor capable of moving along the line cursor is also displayed in superposition with the line cursor, which is in turn displayed in superposition with a sectional view to be displayed next to the scout view, and this point cursor is positioned to a predetermined position of the sectional image so that a final sectional image can be displayed while the portion of this point cursor thus positioned is in agreement with the center of the screen in the horizontal direction.
In the magnetic resonance imaging apparatus having the construction as described above, however, the sectional image is so displayed as to be positioned to the center of the screen in the horizontal direction, but positioning in the vertical direction of the screen has not been taken into consideration. Accordingly, a desired sectional image (final sectional image) is displayed a little upward or downward on the screen depending on the position of the object inside the gantry.
To solve this problem, an imaging technique has been proposed recently which first displays a sectional image (the final sectional image described above) positioned a little upward or downward, displays then the point cursor in superposition with this sectional image, and positions the point cursor to a predetermined portion so that the predetermined portion can be positioned to the center of the screen in the vertical direction and the desired image can be displayed.
However, this technique invites another problem that the number of sectional images to be displayed at a preliminary stage must be increased by one so as to obtain or designate a desired sectional image, and the procedure becomes too much complicated.